What do you get if you have two episodes to fill with no guest actors and no new sets?

Well in the weird world of Lime Grove 1964, you get The Edge of Destruction - a veritable cryptic crossword with clues from another, different cryptic crossword.

This is, of course, the one where Susan turns sinister scissor sister, Ian seems to have been at the TARDIS brown ale, the Doctor - even with a head wound - still wins Gallifrey's Fastest Butler, and poor old Babs has to hold it all together, despite her pathological fear of Salvador Dali.

Even the Fornicator can't help them as they try to discover what the heck is going on (and what the writer has been smoking) until, finally, the solution springs to mind.

So can Jim and Martin make sense of the sentient ship's clues or will the story leave them on the edge of nervous destruction?